Densely populated, high resolution arrays of radiation detectors are typically cooled during use to cryrogenic temperatures. This requires that a large number of array generated analog signals be coupled out of the cryrogenically cooled stage to an analog signal processor. This analog signal processor is normally maintained in a relatively much warmer environment than the detector array and in fact may generate a substantial amount of heat during its operation. Conventional imaging systems typically employ a plurality of electrical conductors to couple the array signals out of the cold stage.
It has been found that such conventional coupling techniques introduce several significant problems into the design and subsequent operation of high resolution imaging systems. One problem is related to the limited bandwidth of electrical conductors, resulting in a requirement that a large number of electrical conductors be employed. This results in added weight, crosstalk between conductors and an increase in the overall noise budget of the system. Electrical conductors also have inherent length limitations at the relatively high frequencies and low amplitudes of typical array signal outputs, resulting in the requirement that the signal processing electronics be positioned relatively near to the cold stage. This in turn increases the heat load of the cold stage. Furthermore, these inherent disadvantages of electrical conductors militate against the provision of spatially distributed and redundant signal processing electronics. That is, to provide redundant processing nodes requires a corresponding increase in the number of electrical conductors, thereby increasing at least the noise threshold, weight and heat load of the system.
In that such high resolution imaging systems are often employed on aircraft and satellite platforms it can be realized that an overall reduction in system weight, heat and electrical noise are objects of the invention. A further object of the invention is the provision of a capability to readily achieve a high degree of imaging system reliability, such as that achieved through the use of distributed and redundant signal processing nodes or through the use of redundant signal paths between the imaging array and a signal processor.